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Given a set of players P, a set of indivisible resources R, and a set of non-negative values { v pr } p ∈ P , r ∈ R , an allocation is a partition of R into disjoint subsets { C p } p ∈ P so that each player p is assigned the resources in C p . The max-min fair allocation problem is to determine the allocation that maximizes min p ∑ r ∈ C p v pr . In the restricted case of this problem, each resource r has an intrinsic value v r , and v pr = v r for every player p who desires r and v pr = 0 for every player p who does not. We study the restricted max-min fair allocation problem in this paper. For this problem, the configuration LP has played an important role in estimating and approximating the optimal solution. Our first result is an upper bound of 3 21 26 on the integrality gap, which is currently the best. It is obtained by a tighter analysis of the local search of Asadpour et al. [TALG'12]. It remains unknown whether this local search runs in polynomial time or not. Our second result is a polynomial-time algorithm that achieves an approximation ratio of 4 + δ for any constant δ ∈ (0 , 1) . Our algorithm can be seen as a generalization of the aforementioned local search. [ABSTRACT FROM AUTHOR]

In this experiment, the rare earth Gd element was added to Finemet alloy to observe the microstructure and soft magnetic properties. The experimental results showed that the samples with the addition of 0.5% Gd and 1.0% Gd can be quenched and cast normally, and the MS of Fe73Cu1Nb3Si13.5B9Gd0.5 alloy was 10.41% higher than that of Finemet. After annealing, crystal grains of about 10 nm were formed. The μi and μm values of Fe73Cu1Nb3Si13.5B9Gd0.5 alloy were 25.51% and 22.23% higher, respectively, and the coercivity HC was reduced by 12.19% compared to Finemet. At 1 kHz, the μe value of Fe73Cu1Nb3Si13.5B9Gd0.5 alloy at room temperature was 14.57% higher than that of Finemet, while the μe reached 162.34 k and 142.42 k at 90 °C and 150 °C (24% and 29.51% higher, respectively). The Fe72.5Cu1Nb3Si13.5B9Gd1.0 alloy had the best performance at 100 kHz, with higher μe values than Finemet across the ambient temperature range of 30 °C to 150 °C. After tension annealing, the μe values of Fe72.5Cu1Nb3Si13.5B9Gd1.0 alloy were 20–30% higher than those of Finemet. [ABSTRACT FROM AUTHOR]

The study aimed to explore sexual risk behaviours and the correlates of condom use with casual sex partners among drug users in China. Data were collected from 901 eligible drug users (504 men and 397 women) from 2014 to 2015 in Jiangsu, China. Methamphetamine was the most used drug (91.8%) among the participants. The proportion reporting consistent condom use was 4.1 and 11.9% with steady and casual sex partners, respectively. Compared to women, men were more likely to have had their first sex at age ≤16 years (40.3 versus 25.6%), had both steady and casual sex partners (68.0 versus 28.9%), had one night stand partners (54.6 versus 17.4%), had sex under the influence of drugs often (29.8 versus 3.6%). Multiple logistic regressions indicated that inconsistent condom use with casual sex partners was associated with older age, having drug use friends as casual sex partners, while having always used condoms was associated with having never had sex under the influence of drugs, having sought casual sex less frequently, and using condoms at first sex. The findings highlight the need for future gender-specific efforts toward tailoring prevention and treatment programmes to reduce sexual risk behaviours among drug users in China. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to examine associations between nicotine, alcohol, and drug use, as well as key demographic variables, with barriers to antiretroviral therapy (ART) adherence among people living with HIV (PLHIV) in Guangxi, China. Method: Cross-sectional survey data were obtained from 2,095 PLHIV in Guangxi, China, among whom 61.2% were male (n = 1283) and 38.8% were female (n = 812). Participants provided information on substance use history and four types of barriers to ART adherence (symptomatic, emotional, forgetful, and time management barriers). Multivariate regression was used to analyze associations between substance use and perceived barriers to adherence. Results: A minority of participants reported current substance use, with 38.1% (n = 798) using nicotine, 30.7% (n = 644) using alcohol, and 6.6% (n = 138) using illicit drugs. A small but significant proportion of participants reported having quit nicotine, alcohol, and drug use following HIV diagnosis (10.0%, 8.5%, and 9.5%, respectively). Multivariate regression indicated that current drug use was associated with symptomatic, emotional, forgetful, and time management barriers to adherence; current alcohol use was associated with symptomatic, forgetful and time management barriers. Age, ethnicity, official residential status, employment status, duration of being on ART, ability to pay medical expenses, and perceived attitudes of healthcare providers were associated with one or more types of barriers. Conclusions: Psychosocial and behavioral health interventions designed to improve ART adherence in China may benefit from incorporating substance use treatment and care for current users. [ABSTRACT FROM AUTHOR]

Low thermal stability and the shortage of core leakage strongly limit the application of conventional energy storage microcapsules. This study focuses on a novel strategy to develop a new phase change material with excellent thermal durability without core leakage. The new phase change materials is a P(BeA-co-MMA) copolymer microcapsule with crystalline n -alkane side chains. Under the protection of polymer main chains as the shell or skeleton structure on a nano-scale, the crystalline side chains as the core will no longer suffer loss and will maintain stablity in use. The chemical composition, inner homogeneous structure, thermoregulation properties, crystalline behaviour and thermal stability are discussed. The P(BeA-co-MMA) microcapsules provide energy storage capacity in the temperature range of 48–62 °C with the highest enthalpy of 105.1 J g −1 . The 5% weight loss temperature ( T 5% ) is more than 315 °C, which is high enough to withstand the general polymer processing temperature to open the possibility of developing energy storage modified fibre and polymer materials as functional fillers. [ABSTRACT FROM AUTHOR]

Sexual risk behaviors by people living with HIV (PLHIV) can result in secondary HIV transmission and other health problems. Given the dearth of research on age differences in sexual behaviors among PLHIV, the objective of the study is to compare sexual risk behaviors and related factors among PLHIV by age groups. Data used in the current study were derived from a cross-sectional survey conducted from 2012 to 2013 in Guangxi, China. PLHIV were selected randomly from 12 sites with the largest number of HIV/AIDS cases. The 2,987 PLHIV completing the survey were included in the study. Participants were asked about key sociodemographic characteristics, health condition, same-sex behavior, and sexual risk behaviors (number of sex partners, condom use consistency, and change in condom use after HIV diagnosis). Univariate logistic regression analyses were conducted to evaluate associations of sexual risk behaviors with age and other factors. Those variables with ap-value of less than 0.2 were entered into multivariate logistic regression models. All statistical analyses were conducted using SAS 9.4. Differences in sexual risk behaviors across age groups were observed. Compared with their younger counterparts, who were ≥ 50 years of age were more likely to have multiple partners, use condoms inconsistently, and use condoms less than before HIV diagnosis. Moreover, lower education attainment, being in the lowest or highest category of income, having a sero-concordant or sero-unknown steady partner or no steady partner, and having contracted HIV from steady or casual/commercial partners, or through injection drug use appeared to be predictive of at least one of the sexual risk behaviors examined in the study. The findings call for HIV prevention interventions to be tailored to different age groups. The interventions that can help reduce unprotected sex among older PLHIV are urgently needed. [ABSTRACT FROM AUTHOR]

Both stigma and social support have been identified to be associated with HIV status disclosure among people living with HIV. This study aimed to examine cross-sectional associations of perceived social support and multiple types of stigma with both disclosure to various target groups and timing of disclosure among parents living with HIV (PLHIV) in Guangxi, China. Cross-sectional data from 1254 PLHIV in Guangxi, China were analyzed. Measures included demographics, disclosure to specific groups (steady partner/spouse, children, family and others) and timing of disclosure, perceived social support, and three types of HIV-related stigma (perceived, internalized, and enacted stigma). Logistic regression analyses were performed to identify the associations of interest. The participants who reported higher levels of perceived social support were more likely to have disclosed to steady partner/spouse, family or others. Those who experienced enacted stigma were more likely to have disclosed to children or family. Those who were married/cohabitating were more likely to have disclosed to steady partner/spouse, and less likely to have disclosed to children, family or others. Older PLHIV were less likely to have disclosed to steady partner/spouse, or family. Those who had a job were more likely to have disclosed to steady partner/spouse. Perceived social support appeared not to be associated with timing of disclosure. Those who disclosed within a shorter time after diagnosis were more likely to be women or have disclosed to steady partner/spouse, and less likely to have higher perceived stigma or have disclosed to family. Interventions are needed to help reduce the negative effect of perceived stigma at both family and community levels and to help enhance perceived social support in general and emotional support in particular among PLHIV, especially males and older adults. [ABSTRACT FROM PUBLISHER]

Background:Existing research has suggested a positive role of social support in reducing drug use among female sex workers (FSWs). However, there is limited research on the role of social support in amphetamine-type stimulant (ATS) use among FSWs in China. This study explored the present situation of ATS use among FSWs in Guangxi, China and examined the associations of different types of social support from different sources with ATS use. Method:A sample of 1022 FSWs was recruited from 56 commercial sex venues in Guangxi Autonomous Region in China. Bivariate comparison was used to compare demographic characteristics and source of emotional or tangible social support across frequency of ATS use among FSWs. The relationship between social support and ATS use was examined using multiple ordinal logistic regression models controlling for the potential confounding effects of demographic variables. Results:The multiple ordinal logistic regression indicated that FSWs who were from younger age groups (aOR = 10.88 for age group <20; aOR = 2.80 for age group 20–23), and from all higher-income venues (aOR = 1.96 for venue level 1; aOR = 2.28 for venue level 2; aOR = 1.81 for venue level 3) tended to use ATS more frequently. They also tended to use ATS more frequently when they depended on their boyfriends (aOR = 1.08) for emotional support or on their co-workers for tangible support (aOR = 1.17). Conclusions:Different types of social support from different sources can be either positively or negatively associated with ATS use among FSWs, therefore, the future intervention efforts should differentiate and target different types and different sources of social support in response to the living and work conditions of FSWs. [ABSTRACT FROM PUBLISHER]

Perfluorinated dinuclear metal complexes, [M2L2] (M = Ni2+ (1), Cu2+ (2), and H2L = 1,5-dihydroxy-1,5-bis(pentafluorophenyl)-1,4-pentadien-3-one), were examined as host crystals to encapsulate alcohol molecules. Complex 1 was crystallized from EtOH and MeOH to give unique single crystals 1·2EtOH·2H2O and 1·8MeOH, respectively, showing a unique hydrogen bonded motif of solvent molecules due to the hydrophobic crystalline cavities surrounded by the pentafluorophenyl moieties on the dinuclear Ni2+ sites. This open and specific cavity on the metals is not suitable for EtOH or H2O in the crystallization process whereas MeOH, a physiologically harmful substance used in industry, is effectively and selectively encapsulated. The encapsulated MeOH molecules form tetrameric clusters that are stabilized by hydrogen bonding. Vapor adsorption of the powder samples shows reversible and accelerated recognition of alcohol only for the perfluorinated complex 1, while two coordination solvates were observed for 2. [ABSTRACT FROM AUTHOR]

In this paper, we synthesized MC(BeA-co-MMA) copolymer microcapsules through suspension polymerization. The pendent n-behenyl group of BeA is highly crystalline, and it acts as the side-chain in the structure of BeA-co-MMA copolymer. The highly crystalline n-behenyl side-chain provides BeA-co-MMA copolymer thermal-energy-storage capacity. In order to investigate the correlation between the thermal properties and crystal structure of the BeA-co-MMA copolymer, the effects of monomer ratio, temperature changing and the changing rate, as well as synthesis method were discussed. The monomer ratio influenced crystal transition behavior and thermal properties greatly. The DSC results proved that when the monomer ratio of BeA and MMA was 3:1, MC(BeA-co-MMA)3 showed the highest average phase change enthalpy ΔH (105.1 J·g–1). It indicated that the n-behenyl side-chain formed a relatively perfect crystal region, which ensured a high energy storage capacity of the copolymer. All the DSC and SAXS results proved that the amount of BeA had a strong effect on the thermal-energy-storage capacity of the copolymer and the long spacing of crystals, but barely on the crystal lamella. It was found that MMA units worked like defects in the n-behenyl side-chain crystal structure of the BeA-co-MMA copolymer. Therefore, a lower fraction of MMA, that is, a higher fraction of BeA, contributed to a higher crystallinity of the BeA-co-MMA copolymer, providing a better energy storage capacity and thermoregulation property. ST(BeA-co-MMA) copolymer sheets with the same ingredients as microcapsules were also prepared through light-induced polymerization aiming at clarifying the effect of the synthesis method. The results proved that the synthesis method mainly influenced the copolymer chemical component, but lightly on the crystal packing of the n-behenyl side-chain. [ABSTRACT FROM AUTHOR]

Most of the phase change materials (PCMs) have been limited to use as functional additions or sealed in containers, and extra auxiliary equipment or supporting matrix is needed. The emergence of 3D printing technique has dramatically advanced the developments of materials and simplified production processes. This study focuses on a novel strategy to model thermal energy storage crystalline gels with three-dimensional architecture directly from liquid resin without supporting materials through light-induced polymerization 3D printing technique. A mask-projection stereolithography printer was used to measure the 3D printing test, and the printable characters of crystalline thermal energy storage P(SA-DMAA) gels with different molar ratios were evaluated. For the P(SA-DMMA) gels with a small fraction of SA, the 3D fabrication was realized with higher printing precision both on milli- and micro- meter scales. As a comparison of 3D printed samples, P(SA-DMAA) gels made by other two methods, post-UV curing treatment after 3D printing and UV curing using conventional mold, were prepared. The 3D printed P(SA-DMAA) gels shown high crystallinity. Post-UV curing treatment was beneficial to full curing of 3D printed gels, but did not lead to the further improvement of the crystal structure to get higher crystallinity. The P(SA-DMAA) crystalline gel having the highest energy storage enthalpy was developed, which reached 69.6 J·g−1. Its good thermoregulation property in the temperature range from 25 to 40 °C was proved. The P(SA-DMAA) gels are feasible for practical applications as one kind of 3D printing material with thermal energy storage and thermoregulation functionality. [ABSTRACT FROM AUTHOR]

Metastable phase has great potential in searching hydrogen storage alloys. In this work, high pressure solidification has been successfully used to realize the supersaturation of Ti in YFe 2 based C15 Laves phase to obtain a metastable Y 0.7 Zr 0.24 Ti 0.06 Fe 2 alloy. The segregation of Ti, Y, Zr and related multi-phase formation were substantially suppressed and the obtained HPS alloy contained a primary C15 phase(C15–1) and a secondary C15 phase(C15–2) with 77.1% and 22.9% of the total content, respectively. Meanwhile, the hydrogen absorption and desorption capacities increased substantially. This study proves that the combination of high-pressure solidification and alloying is a very effective method for exploring new hydrogen storage materials with metastable structure and high performance. • The supersaturation of Ti in YFe2 based C15 Laves phase is released. • The segregation of Ti, Y, Zr and related phases are substantially suppressed. • Hydrogen absorption/desporption capacities reach 2.06 wt%/0.69 wt% for HPS alloy. • Ab/desorption capacities remain 1.91%/0.62% and 1.87%/0.59%(wt.) in following cycles. • Combining HPS and alloying is effective for exploring new hydrogen storage material. [ABSTRACT FROM AUTHOR]

This work focuses on a broad class of facility location problems in the context of adaptive robust stochastic optimization under the state-dependent demand uncertainty. The demand is assumed to be significantly affected by related state information, such as the seasonal or socio-economic information. In particular, a state-wise ambiguity set is adopted for modeling the distributional uncertainty associated with the demand in different states. The conditional distributional characteristics in each state are described by a support, as well as by mean and dispersion measures, which are assumed to be conic representable. A robust sensitivity analysis is performed, in which, on the one hand, we analyze the impact of the change in ambiguity-set parameters (e.g., state probabilities, mean value abounds, and dispersion bounds in different states) onto the optimal worst-case expected total cost using the ambiguity dual variables. On the other hand, we analyze the impact of the change in location design onto the worst-case expected second-stage cost and show that the sensitivity bounds are fully described as the worst-case expected shadow-capacity cost. As for the solution approach, we propose a nested Benders decomposition algorithm for solving the model exactly, which leverages the subgradients of the worst-case expected second-stage cost at the location decisions formed insightfully by the associated worst-case distributions. The nested Benders decomposition approach ensures a finite-step convergence, which can also be regarded as an extension of the classic L-shaped algorithm for two-stage stochastic programming to our state-wise, robust stochastic facility location problem with conic representable ambiguity. Finally, the results of a series of numerical experiments are presented that justify the value of the state-wise distributional information incorporated in our robust stochastic facility location model, the robustness of the model, and the performance of the exact solution approach. [ABSTRACT FROM AUTHOR]

Mechanochromic elastomers that exhibit force‐induced cross‐linking reactions in the bulk state are introduced. The synthesis of segmented polyurethanes (SPUs) that contain difluorenylsuccinonitrile (DFSN) moieties in the main chain and methacryloyl groups in the side chains was carried out. DFSN was selected as the mechanophore because it dissociates under mechanical stimuli to form pink cyanofluorene (CF) radicals, which can also initiate the radical polymerization of methacrylate monomers. The obtained elastomers generated CF radicals and changed color by compression or extension; they also became insoluble due to the mechanically induced cross‐linking reactions. Additionally, an SPU containing diphenylmethane units also exhibited highly sensitive mechanofluorescence. To the best of our knowledge, this is the first report to demonstrate damage detection ability and changes in the mechanical properties of bulk elastomers induced by simple compression or extension. [ABSTRACT FROM AUTHOR]

Mechanochromic elastomers that exhibit force‐induced cross‐linking reactions in the bulk state are introduced. The synthesis of segmented polyurethanes (SPUs) that contain difluorenylsuccinonitrile (DFSN) moieties in the main chain and methacryloyl groups in the side chains was carried out. DFSN was selected as the mechanophore because it dissociates under mechanical stimuli to form pink cyanofluorene (CF) radicals, which can also initiate the radical polymerization of methacrylate monomers. The obtained elastomers generated CF radicals and changed color by compression or extension; they also became insoluble due to the mechanically induced cross‐linking reactions. Additionally, an SPU containing diphenylmethane units also exhibited highly sensitive mechanofluorescence. To the best of our knowledge, this is the first report to demonstrate damage detection ability and changes in the mechanical properties of bulk elastomers induced by simple compression or extension. [ABSTRACT FROM AUTHOR]

The current study examined the effects of a silent rapid reading skills training intervention on the reading rate and reading achievement of primary school students in China in order to determine the efficacy of the intervention and explore potential gender differences. A total of 108 Chinese primary school students were randomly assigned by the classroom to either an experimental (n = 54) or control (n = 54) condition. Students in the experimental group completed 12 sessions of rapid reading skills training designed to increase their ability to rapidly read Chinese text in silence. Students in the control group engaged in regular Chinese language curriculum for the same time period. After the three-week intervention period, students in the experimental group displayed significantly greater silent reading speed of Chinese characters (M = 1331.26 characters per minute) compared to students in the control group (M = 617.48 characters per minute; p <.001). Children in the intervention group also displayed a significantly greater effective reading rate (F = 87.11, p <.001, partial η2 = 0.46) at post-test compared to the control. Male students displayed greater increases in reading speed than female students. Neither intervention effect nor gender difference was evident for reading comprehension. Implications for educational interventions designed to increase silent reading speed among Chinese students are discussed. [ABSTRACT FROM AUTHOR]

Certain patients with anorectal malformations (ARMs) continue to suffer from postoperative dysphoria. The enteric nervous system (ENS) is closely associated with defecation. The purinergic receptor P2Y2 (P2Y2) and Hu antigen D (HuD) proteins contain multiple motifs that enable their activation and direct coupling to integrin and growth factor receptor signaling pathways; thus, they may serve as key points in ENS development. The aim of the present study was to investigate the expression pattern of P2Y2 and HuD proteins during anorectal development in ARM embryos. The embryogenesis of ARM in rats was induced by ethylenethiourea (ETU) on the 10th gestational day. The expression patterns of P2Y2 and HuD proteins were evaluated by immunohistochemistry and western blot analysis in normal, ETU and ARM rat embryos on embryonic days E17, E19 and E21; their mRNA levels were assessed via reverse transcription-quantitative polymerase chain reaction (RT-qPCR) of the distal rectum of fetal rats. Immunohistochemistry of the distal rectum demonstrated that on E17, the expression levels of the two proteins were not different between the three groups. On E19, the expression of HuD was significantly decreased in the ARM group. On E21, the two proteins were significantly decreased in the ARM group. Additionally, the expression levels of the two proteins on E17 were significantly lower than on E21 in the ARM group. Western blotting and RT-qPCR also revealed that the P2Y2 and HuD proteins and mRNA expression levels were significantly decreased in the ARM groups when compared with the normal group on E17 and E21 (P<0.01). Thus, the present study demonstrated that downregulation of P2Y2 and HuD may partly be related to the development of the ENS in ARM embryos. [ABSTRACT FROM AUTHOR]

Keywords: electron paramagnetic resonance; mechanochromism; polymer mechanochemistry; polyurethanes; self-strengthening EN electron paramagnetic resonance mechanochromism polymer mechanochemistry polyurethanes self-strengthening 8555 8555 1 04/01/21 20210406 NES 210406 B Mechanofunctional polymers b that exhibit color change, fluorescence, and self-strengthening ability were developed by Hideyuki Otsuka et al. in their Communication on page 8406. Electron paramagnetic resonance, mechanochromism, polymer mechanochemistry, polyurethanes, self-strengthening Inside Back Cover: Segmented Polyurethane Elastomers with Mechanochromic and Self-Strengthening Functions (Angew. [Extracted from the article]

Electron paramagnetic resonance, mechanochromism, polymer mechanochemistry, polyurethanes, self-strengthening Innenrücktitelbild: Segmented Polyurethane Elastomers with Mechanochromic and Self-Strengthening Functions (Angew. Keywords: electron paramagnetic resonance; mechanochromism; polymer mechanochemistry; polyurethanes; self-strengthening EN electron paramagnetic resonance mechanochromism polymer mechanochemistry polyurethanes self-strengthening 8639 8639 1 04/01/21 20210406 NES 210406 B Mechanofunktionelle Polymere b , die einen Farbwechsel, Fluoreszenz und die Fähigkeit zur Selbstverfestigung aufweisen, werden von Hideyuki Otsuka et al. in ihrer Zuschrift auf S. 8487 vorgestellt. [Extracted from the article]